Remove setting of version/release from releasenotes

Release notes are version independent, so remove version/release
values. We've found that projects now require the service package
to be installed in order to build release notes, and this is entirely
due to the current convention of pulling in the version information.

Release notes should not need installation in order to build, so this
unnecessary version setting needs to be removed.

This is needed for new release notes publishing, see
I56909152975f731a9d2c21b2825b972195e48ee8 and the discussion starting
at
http://lists.openstack.org/pipermail/openstack-dev/2017-November/124480.html
.

Change-Id: I73e1f718df61232fafee64b34b397a3867f74171

releasenotes/source/conf.py

@@ -13,8 +13,6 @@
 #
 # os-vif Release Notes documentation build configuration file
 
-from os_vif.version import version_info
-
 # -- General configuration ------------------------------------------------
 
 # Add any Sphinx extension module names here, as strings. They can be
@@ -35,15 +33,12 @@ master_doc = 'index'
 project = u'os-vif release Notes'
 copyright = u'2017, OpenStack Foundation'
 
-# The version info for the project you're documenting, acts as replacement for
-# |version| and |release|, also used in various other places throughout the
-# built documents.
-#
-# The short X.Y version.
+# Release notes do not need a version in the title, they span
+# multiple versions.
 # The full version, including alpha/beta/rc tags.
-release = version_info.version_string_with_vcs()
+release = ''
 # The short X.Y version.
-version = version_info.canonical_version_string()
+version = ''
 
 # The name of the Pygments (syntax highlighting) style to use.
 pygments_style = 'sphinx'